Microsoft denied it was excluding websites or censoring information from its Bing search engine results for Chinese-language users in the US, after censorship blog GreatFire.org first brought up the issue.

Author Charlie Smith, who is associated with the blog, told The Guardian that he found the differences while searching for FreeWeibo.com, a tool that allows uncensored search of Chinese blogs. “FreeWeibo's homepage — which did appear on Google — would not appear on Bing”, he said.

The British publication also noticed that Chinese-language searches for politically controversial China-related topics produced unforeseen results.

An English-language Bing search for the Dalai Lama is led by a link to his official website, followed by links to his Wikipedia, Facebook, and Twitter pages. Whereas a Chinese-language search for the same displays a link to information on a documentary compiled by CCTV, China’s state-owned broadcaster, followed by a link to Wikipedia rival Baidu Baike, which is said to be heavily censored.

Stefan Weitz, senior director for Bing, denied the charge that Microsoft is censoring information overseas, citing a technical problem instead. “Due to an error in our system, we triggered an incorrect results removal notification for some searches noted in the report but the results themselves are and were unaltered outside of China”, he said.

Though Weitz did not say if the technical error had been fixed, he said that the Microsoft's search engine does not apply China's legal requirements to searches conducted outside of the country. Meanwhile, Microsoft officials in Beijing refused to elaborate.